PB2203: INCIDENCE AND PREVALENCE OF MYELOFIBROSIS IN GERMANY: A RETROSPECTIVE CLAIMS DATA ANALYSIS
Authors: Sophia Junker, Alexander Slowley, Joachim Göthert, Tim D’estrube, Kelesitse Phiri, Martin Krammer, Lena Sofie Weinmann, Florian Karl, Suzanne Landi, Sabrina Müller, Boris Gorsh
Journal: HemaSphere (2023)

Topic: 16. Myeloproliferative neoplasms - Clinical Background: Myelofibrosis (MF) is a rare type of hematologic neoplasia belonging to the group of myeloproliferative neoplasms that includes primary de novo disease and disease secondary to essential thrombocythemia (ET) or polycythemia vera (PV). Prevalence from studies conducted in Europe and the US ranges from 2.5-5.7/100,000 persons. To date, robust data on the epidemiology of MF in Germany are lacking. Aims: This study investigated the epidemiology of MF in Germany, including prevalence, incidence, and patient characteristics. Methods: This retrospective study used anonymized claims data from 1/1/2010-12/31/2021, provided by a German statutory health insurance fund (AOK PLUS) insuring ≈3.4 million persons in Saxony and Thuringia (4% of the overall German population). From the full data set, we identified all persons with ≥1 inpatient diagnosis or 2 outpatient diagnoses of ICD-10-GM code D47.1, D47.4, and/or C94.6 in 2 different quarters within 12 months who were continuously insured in 2021 and alive on 12/31/2021. In the base case scenario for MF prevalence estimation, only patients with ≥1 diagnosis of ICD-10-GM D47.4 or treatment with Janus kinase (JAK) inhibitors (fedratinib, ruxolitinib) and no documented diagnosis of ET or PV at any time following the first MF diagnosis were counted. Three further sensitivity selection scenarios without the JAK inhibitor criterion were applied: ≥1 inpatient or 2 confirmed outpatient diagnoses of D47.4 were necessary; ET/PV criterion was removed, but no D47.1/C94.6 was observed after the last D47.4 diagnosis; and ET/PV criterion was removed, but a documented bone marrow biopsy was needed before the last diagnosis of ICD-10-GM D47.4 (Figure 1). Analogous to the prevalence scenarios, MF incidence in 2021 was assessed using the above base case and sensitivity selection scenarios to identify MF from 1/1/2021-12/31/2021. Patients were required to have no documentation of any MF-relevant diagnosis code from 1/1/2010-12/31/2020 and continuous insurance throughout 2020 (ensuring a minimum diagnosis-free period of 12 months). Point prevalence on 12/31/2021 and cumulative incidence in 2021 were reported and extrapolated to the overall German population (standardized by published age and sex distribution in the reference populations). Patient characteristics were assessed as of 12/31/2021 or at the index diagnosis for the prevalent and incident cohorts, respectively. Results: In the base case scenario, 371 patients with MF were identified during the study period (median age, 68 years; female, 49.9%). Standardized point prevalence on 12/31/2021 based on the total German population was 11.0/100,000 persons. Alternative identification strategies resulted in lower and upper bounds of MF prevalence of 9.9 and 12.4 per 100,000 (Figure 1). Cumulative incidence of MF in 2021 was estimated at 1.6/100,000 persons, with a range based on sensitivity scenarios of 1.2-1.8/100,000. Median age at incident diagnosis was 69 years, and 46.3% of incident patients were female. Summary/Conclusion: To our knowledge, this is the first study investigating the epidemiology of MF based on German claims data. Prevalence rates of MF were generally higher than previously reported, which may be explained by improved diagnostics, increased offerings for preventive checkups, and the classification change of prefibrotic MF by the World Health Organization (WHO) in 2016. Diagnostic coding routines in Germany should reflect subtypes of MF (prefibrotic, post-ET, post-PV, primary MF) per the current WHO classification.Keywords: Myelofibrosis, Epidemiology, Incidence